The primary objective of the proposed research is to develop new methodology for organic synthesis based on the organometallic chemistry of manganese. Results obtained to date indicate that aromatic systems, conjugated dienes and carbon-hydrogen bonds can be activated by manganese in fundamentally new and unique ways. Specific aims are to use these procedures for development of (1) methods for stepwise reductions of substituted arenes to 1,3-cyclohexadienes and cyclohexenes with control of regiochemistry and with concomitant stereo- and regiospecific functionalization, (2) completely new methods of arene substitution wherein substituents can be introduced from organocuprates or from organic electrophiles under basic or nucleophilic conditions, and (3) techniques for carrying out regiospecific and stereospecific electrophilic and nucleophilic substitutions on acyclic dienes. Numerous other applications can be envisioned and the long range goal is the development of this chemistry in a broad and general way for practical utility in organic synthesis. The general reactions to be developed will complement existing synthetic methodology and will be generally applicable to the synthesis of a diverse class of naturally occurring and/or biologically active systems. As detailed in section D, potential utility can be envisioned in the synthesis of certain carcinogenic polymethylated polycyclic aromatic hydrocarbons and the metabolically derived polycyclic aromatic diol epoxides, various pheremones, terpenoids, and alkaloids and specific classes of cytochalasans (compounds which affect a wide range of biological processes including cytokinesis, phagocytosis, and platelet aggregation).